A controlled prospective outcome study of implantable electrical stimulation with spinal instrumentation in a high-risk spinal fusion population

Abstract

Study design: A series of 65 instrumented patients without stimulation were compared with a later series of 65 patients with instrumentation and implantable electrical stimulation. The groups were evaluated for risk factors, age, diagnostic groups, levels fused, and radiographic and clinical success.

Objectives: To test the efficacy of electrical stimulation in instrumented high-risk lumbar fusions.

Summary of background data: Spinal instrumentation and implantable electrical stimulation have been shown to improve fusion success rates.

Methods: All patients were instrumented via pedicle screws and autologous bone graft. Diagnostic groups were evaluated, and the risk factors in each group were identified and compared. Postoperation management and follow-up regimen were similar in each group. Radiographs were evaluated via Dawson's criteria and confirmed by an independent radiologist. Clinical success was evaluated via the Modified Smiley-Webster Scale and confirmed by a second orthopedic surgeon.

Results: Fusion success was 95.6% in the stimulated group compared with 87% in the nonstimulated group (P = 0.05). Clinical success was 91% in the stimulated group and 79% in the nonstimulated group (P = 0.02). In a workers' compensation subset, fusion success was 93% in the stimulated group and 81% in the nonstimulated group. Clinical success was 57% in the stimulated group and 46% in the nonstimulated group.

Conclusions: The results from using both instrumentation and electrical stimulation in a high-risk pool of patients show a statistically significant difference, with higher rates of fusion and clinical success than in a similar pool that did not receive stimulation.